Compress one file to GZIP or restore its bytes locally, with output limits and checksum validation.
Your content stays on your device Free, with no account
GZIP Compressor / Decompressor · files stay on your deviceNo uploads
No file selected.
Up toone file,64 MiB per file /64 MiB total. New selection replaces the source. File input values are reset after capture; retained selections remain visible below.
Choose files to begin. Nothing is uploaded.
File queue & settings
Choose a source or try the sample.
Supported scope & limits
One input≤64 MiB; actual output≤128 MiB. GZIP compresses/restores one byte stream, not a multi-file folder archive. Compression uses self-hosted fflate; validation/restoration requires native GZIP DecompressionStream support. CRC/length and optional header checks apply. Multi-member streams with different combined lengths reject. Restored filename derives from the selected source name, never a GZIP header path. No extension/content-format conversion is inferred.
Operations use a local worker with a 60-second deadline. Bounded processing can still exceed a small device’s memory; errors leave no enabled partial result. ZIPs are data containers, not encryption. Keep original files; all actions generate downloads or reports.
Self-hosted archive engine
fflate 0.8.3, MIT license. No CDN, server processing or input history. Older tools retain their existing library.
SOURCE FILES / DIRECTORY
Review the selection
No files selected.
Original retained files
Selections and queue order affect naming and processing. Remove changes only this in-memory queue; source files on disk remain untouched. Filter does not change selection. Lists paginate 50 rows; exports include the full applicable result.
Choose or drop local files, or try the generated sample. Check filename, size and actual loading/ready/error status.
Review the file queue or ZIP directory. Select applicable files, adjust settings and inspect naming/metadata before processing.
Run the selected local operation. Stop cancels the worker; edits or source changes invalidate old outputs.
Review actual result details and download the verified file or full report. Original files on disk remain unchanged.
PRIVATE BY DESIGN
Why use this tool?
Your files are never uploaded to any server. Archive compression, extraction, naming, metadata inspection and duplicate-content comparison run locally with self-hosted code. No account, external processing service or application input history is used.
Tool inputs stay in your browser. Only your theme preference is saved on this device.
A few things worth knowing
What formats and limits are supported?
One input≤64 MiB; actual output≤128 MiB. GZIP compresses/restores one byte stream, not a multi-file folder archive. Compression uses self-hosted fflate; validation/restoration requires native GZIP DecompressionStream support. CRC/length and optional header checks apply. Multi-member streams with different combined lengths reject. Restored filename derives from the selected source name, never a GZIP header path. No extension/content-format conversion is inferred.
Does this modify or delete my original files?
No. Files are read from the user-selected browser File objects. Renaming/extraction/compression creates downloaded copies. Removing from the queue only releases the in-memory selection. Duplicate Finder produces reports and never deletes source files.
Can all ZIPs, RAR or 7z files be opened?
No. ZIP reader support is explicit: classic unencrypted STORE/DEFLATE with validated safe relative paths. ZIP64, multi-part, encrypted, symlink, self-extracting and other compression methods reject. RAR/7z/TAR support is not claimed. GZIP restores a single data stream; it does not unpack TAR contents.
Does compression always make files smaller?
No. Already-compressed formats such as JPG, PNG, MP4 or ZIP can become slightly larger. The actual generated size is shown. ZIP is a container and does not add password protection. Compression settings never change original content bytes.
How is output integrity handled?
ZIP structure/path checks and declared size budgets precede decoding. Selected extraction and generated ZIP files check actual expanded byte counts and CRC32. GZIP uses the native browser decoder plus CRC/length checks. Duplicate groups use SHA-256 candidates with final byte-for-byte confirmation. Integrity checks are not a malware scan or proof that a file is safe to execute.
